Crystal unit



FIG. 1 is a perspective view from the top of a crystal unit of a new design;

FIG. 2 is a perspective view from the bottom thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a sectional view taken along line 7-7 of FIG. 4 view.

The broken lines shown in the drawings represent unclaimed portions of the crystal unit and form no part of the claimed design. 

The ornamental design for a crystal unit, as shown and described. 